The articles and essays in this blog range from the short to the long. Many of the posts are also introductory (i.e., educational) in nature; though, even when introductory, they still include additional commentary. Older material (dating back mainly to 2005) is being added to this blog over time.

Wednesday, 19 August 2015

Is Consciousness the Brain Carrying Out Computations?

Hilary
Putnam once held the position (i.e., in the 1960s) that consciousness is
literally the brain computing. That also had the implication (for
some people) that it's not necessarily the brain that causes
consciousness: it's computation itself. This is the case even if it's
computation of a particular kind (in conjunction with its physical or
biological implementation) that's required for consciousness. Thus it
followed from this, according to Putnam, that if computation is
everything, then consciousness can occur in a computer or even in
Putnam's own “brain in a vat”. Again, what matters are the
computations, not the physical basis of those computations. (To be
accurate, in his 1967 paper, Putnam hardly refers to consciousness
as such. He talks about “mental states”.)

Daniel
Dennett also argued that the computations of the brain are
consciousness. This doesn't mean that such brain computations result
in consciousness in some kind of causal and temporal sequence. It
means that when the brain's computations occur, so too do conscious
events. They're one and the same thing. Or, as Dennett himself puts
it, it's not a case of brain computations occurring (in what he calls
the “Cartesian Theatre”)
and then we become conscious of those computations. Instead, when
brain-computations occur they actually constitute consciousness. When
the brain computes: that's what consciousness is. That's what we're
aware of when we're conscious; though we aren't necessarily aware of
them as computations (or as anything).

This
is similar to John Searle's view in which he says that there's no
causal and temporal sequence from a brain state to a mental state in that
the mental state is the brain state. The brain state and mental state
occur at one and the same time. It isn't a case of brain state at
time t1
causing mental state at time t2.
Both the brain state and the mental state occur at t1.

The
mental state is the state as experienced from the inside (as it were);
whereas the brain state could (in theory at least) be observed by
neuroscientists. However, it need hardly be said that Searle doesn't
believe that this has anything to do with computations (as
such). In his case, it's a point about the (causal) relations between
the brain and consciousness; not between computations and
consciousness.

Finally,
it needn't be the case that consciousness is always (or at all)
computation. We can substitute all the references to 'computation'
in the above with the words 'brain event' or 'brain state'; as
Putnam himself did in his paper of 1967.